Hello everyone. I have three questions:

1. Has anyone ever replaced the backlighting for the graphics above the exterior light switch (which is to the lower left of the steering wheel)? If so, how is this done?

2. Does anyone know if the outside temperature LCD on the instrument cluster is back lit with a bulb that can be replaced, or is the LCD self lit - needing replacement of the LCD itself? Note: I can still see the temperature, but faintly.

3. Has anyone ever replaced the backlighting for the red/blue HVAC buttons between the center vents? If so, please describe. Per other posts regarding replacement of the thumbwheel lighting - I am assuming that the small glove box above the vents needs removal, but what takes place from there?

Thank you, JD.

1) For the light switch legend, you pull the knob, unscrew the nut that holds the switch, take the plastic trim out and the bulb is there. Bulb is replaceable.

2) Many posts on how to take the IP off. The bulb behind the ODO and is replaceable.

3) If I am not mistaken, all bulbs that dim with the dimmer control (left knob in the IP, next to the ODO) are replaceable on W140. The two lights for Cold/Warm Center air supply are LED's. At least that is what they look like to me. I have not replaced them, but should be easy to check once you have the vents out.
Hope this helps....

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Regards

Mino Erhan Dallas, TX
'97 SL500 40th A.E.
'97 S320
'01 ML320
'85 Peugeot 505 SW
'07 BMW R1200RT
'74 Suzuki GT750

Mino: Thank you for your reply. In regards to my question 3, the red LEDs show which button is selected still light, but the actual red and blue graphics to the buttons do not - thing is that I am not sure if they ever did. But, according to the posts of others on this board - they are supposed to.

So I am thinking that there are probably two parts to the lighting of the buttons - a traditional bulb for the graphics and an LED for the signal. Thank you for your helpful message - the ease of removing the exterior light switch is a relief! Best, JD.

Hello. I tried to remove the knob, but it is not coming off. I tried pulling it straight out but does not detach and I do not want to break anything. Please advise. Thank you.

That is strange, maybe someone else can chime in on the headlight knob removal.

On the center vents..... the legend i.e. the red or blue rectangle or arrow will not illuminate. Only the, what looks like an LED will light up. I checked both my cars.

__________________
Regards

Mino Erhan Dallas, TX
'97 SL500 40th A.E.
'97 S320
'01 ML320
'85 Peugeot 505 SW
'07 BMW R1200RT
'74 Suzuki GT750

Thanks for the additional update. Less work to do!

re: question 2. (temp)
Yes there is a back light bulb for the outside temp. Similar to the speedo and other instrument bulbs.
You do have to pull the entire instrument panel to gain access. Be carefull -- does require (2) special shape puller hooks. Also I had to remove the L AC vent grill and put my hand inside to push forward on the panel while another tech used both of the puller hooks. There is info about IP pulling here on this forum.

Luck to you,

DanielW

Thank you. Too bad MB doesnt package a manual / tools for owners to replace interior bulbs!

Just to be clear on the red / blue HVAC buttons I speak of above. The portions that I would like to know whether are back lit or not are circled. Thanks.

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Yes, the red and blue rectangles on the central vents are back lighted. You have to remove the central vent assembly to access the bulb. My tech did it to change the bulb for the central Parktronic screen on my S 500 L. Problem is I don't remember exactly how to remove those vents.

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A. Rosich
CL 500, 1998
S 500 L, 1998
E 320 T, 1995 [Sadly sold ]

I made hooks to remove my instrument panel on my former 300E from wire coat hanger. I got method from search of forum.

__________________
Earl



1993 190E 2.3
2000 Toyota 4x4 Tundra

thank you rosich and ej.

hello again everyone. they say a picture is worth 1000 words. these are the graphics i was referring to above the light knob. back lit or not? strange enough, i was picking up a new remote key at the dealer today and asked one of the service writers and they said that it is not. i find this hard to believe. thanks.

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The graphics above the headlamp switch do light up. I think you get at the bulb from behind the dash, but removing the knee bolster to do it is no small feat.

Removing the headlamp switch knob is done with a small (very small) flat blade screwdriver. Look up at the knob from below and you'll see a small slot. Press the blade of the screwdriver up into the slot while pulling on the knob and it will come off. However, this isn't going to get you access to the bulb you seek.

To remove the knee bolster, there's one screw accessible via the vent visible at the edge of the dash when you open the door. The grille is removable by hand and you'll see the bolt/screw in there. It faces vertically (attaches to the bottom of the dash).

There's another screw mounted horizontally behind the parking brake release handle - I think it's on the right-hand side. You should see it when you pull the handle out.

There are two more screws up underneath the bolster - they're near the vents.

There may also be one more screw on the firewall to the left of the accelerator pedal.

There are two latches that are found hidden between the bolster and the bottom edge of the dash. Take a small screwdriver and insert it horizontally between the carpet and the bottom edge of the dash and slide it towards the steering wheel. You'll find the latches about 6" to the left the steering wheel center line and more-or-less centered in the bolster on the right side next to the console. There's a little tab that is on the front of the latch - press inward on the carpet and I think you can see it - taking the small screwdriver and wedging gently on that tab should release the latch.

AllData says the latches are screws. They may be screws on some models, but on my '92, they were latches. AllData also says you "hold cover down for access" - there's a little give in all of this stuff - so don't be too afraid to pry or pull to peek and prod. Just be careful not to pry or pull too hard - and don't pry against anything soft.

Once you get the bolster out, you should be able to reach in behind the switch and find the bulb holder. I think it just snaps into the back of the graphics frame.

As for the hot/cold buttons on the center vent - they are also back-lit. To get the vent assembly out is nearly as complicated as the headlamp switch affair.

You must first remove the "upper" glove box (I call it a 'spectacle' box - it's where I keep my sunglasses - some cars have the cell phone control mounted there) - the one above the vent. To do that, you have to pull out the lock assembly for the glove/spectacle box. You need a master key to do this - one with a square head. Put the key in the slot and turn it about 45 degrees. Now take a small drill bit (about 1/16 or a little smaller - AllData says 1.5mm) and insert into the hole you should see in the escutcheon. You know the key is in the right place when you can insert the drill bit - it won't go if the key's not in the right spot. The drill needs to be large enough to be snug in the hole, but you should be able to insert it easily. Use the bottom of the bit (the part you insert into the drill) in the hole - wear gloves or tape over the helix of the bit to prevent cuts on your fingers. Press straight in and possibly wiggle the key/bit a little and the key cylinder should release and can be pulled straight out of the dash. The bit will need to go in about 1" or more. LEAVE THE KEY in the cylinder.

Inside the cylinder bore you should find a phillips screw at the bottom - loosen this screw and the lock assembly can be removed. Just pull it out of the way a bit.

There are 2 screws at the back of the spectacle box that hold it into the dash. Remove those as well. If you have a cell phone controller in the box, you'll have to get that out to gain access to the screws - I have no idea how to remove the control - my car doesn't have one.

Once you get the spectacle case out, there are a couple of screws visible and the vent assembly can be pulled out with ease. It is possible that you'll see the bulb housing when you remove the spectacle box - I'm not sure. If you do - no need to pull the vent assembly - just remove/replace the bulb.

When you reinsert the key, there's a tab on the lock cylinder where the long thin portion of the shaft meets the tumblers area - make sure that tab engages the recess in the lock assembly in the dash. You don't need the pin to reinsert the key - put it back in at the 45 degree angle you removed it at (that's why the tab is important - you can be 180 degrees off) and it will snap into place.

I'll bet money that the same bulb is used in both applications.

Good luck.

If you have small hands you could replace the bulb for the main light switch through the opening after removal of the left air vent.
Mike

thank you everyone for your most helpful knowledge. with exams in two weeks and such that the job is not as easy as originally thought - ill go through with the whole proceedure and report back once my tests are done. ill definately make sure to take pics in the process too. thank you!